1. Field of the Invention
The disclosures herein generally relate to a holding structure for holding a reflecting mirror, a projection optical system unit, an optical engine, and an image projecting apparatus.
2. Description of the Related Art
An image projecting apparatus that uses light from a light source, and generates image light based on image data from a personal computer, a video camera, or the like to project the generated image light on a projection plane such as a screen is known in the related art.
Japanese Unexamined Patent Application Publication No. 2013-64866 discloses an image projecting apparatus. The image projecting apparatus disclosed in Japanese Unexamined Patent Application Publication No. 2013-64866 uses light from a light source, and generates image light. Then, the image projecting apparatus causes a reflecting mirror to reflect the generated image light to project the generated image light on a projection plane.
The reflecting mirror disclosed in Japanese Unexamined Patent Application Publication No. 2013-64866 is held by a reflecting mirror bracket. A structure for holding the reflecting mirror causes the reflecting mirror bracket to rotatably hold the reflecting mirror. In this way, an inclination of the reflecting mirror is adjusted.
In a case where the inclination of the reflecting mirror is adjusted in order to form, on the projection plane, an image of the image light reflected by the reflecting mirror, it may be unable to form the image of the image light on the projection plane when an assembling error of the reflecting mirror or the like is large even if the inclination of the reflecting mirror is adjusted. As a result, quality of the image light may be degraded. For example, color definition of the image light projected on the projection plane may be degraded.